Slopes of the relative linear decrease of genetic variation within populations, estimated from the average heterozygosity (or equivalent quantity for Y chromosome) of each population, as a function of its geographic distance from Addis Ababa (see also Fig. S6 and Table S4)

Chromosome

Markers

Source

Slope (absolute value)

All autosomes + X

783 microsatellites

Ref. 11

6.5 × 10−6

All autosomes + X

650,000 SNPs

Ref. 12

3.8 × 10−6

X chromosomes

Haplotypes

Ref. 12

18.8 × 10−6

Y chromosome

NRY haplogroups

This article

25.7 × 10−6

The decrease has been postulated to be due to drift caused by the serial founder effect (11). Geographic distance in km. All slopes are negative: their absolute values are given in the table.